How many times a day do you pay attention to your breathing? Probably not even once because it is something so habitual, so spontaneous and so universal that it goes unnoticed. But without breathing, no human on earth can survive. While our nose is a medium to exchange atmospheric air and filter out the unwanted substance, the core job of respiration is performed by the lungs. So, today we are going to learn 20 interesting human lungs facts and find out their amazing powers!

Did you know that human lungs are the only organs that can float?

Interesting Human Lungs Facts: 1-5

1. Human lungs are the organs responsible for respiration. Respiration is different than breathing. Breathing involves the act of inhaling oxygen and exhaling carbon dioxide. This is usually accomplished by the nose. Breathing on the other hand is a process of breaking down oxygen so that it can be used by body cells for creating energy. Thus, breathing is a part of respiration because without breathing, oxygen cannot enter our body. Thus, the job of our lungs is to process oxygen.

2. There are two lungs in human body – the right lung and the left lung. These two lungs together weigh 2.9 pounds of 1.3 kilograms. The left lung is lighter than the right lung.

3. The left lung has two lobes and is slightly smaller than the right lung. The right lung on the other hand has three lobes.

4. The structure of left lung differs slightly from the structure of right lung (apart from the difference in the number of lobes). The left lung contains a ‘cardiac notch’. The cardiac notch is a small place designed to accommodate the heart.

5. The total length of the airways running through the two lungs is 1,500 miles or 2,400 kilometers.

Interesting Human Lungs Facts: 6-10

6. The two lungs together contain 300 to 500 million alveoli. What are alveoli? They are tiny and spongy air sacks no thicker than a typical cell (remember that you cannot really see an individual human cell without the help of a powerful microscope) which usually measures 10 micro meters or 10 µm which is actually 10-5m. These alveoli are present at the end of the smallest of airways and are the true sites of carbon dioxide and oxygen exchange.

7. Scientists estimate that the total internal surface area of lungs in adult humans vary between 30-50 sq. meters and 70-10 sq. meters. Converting the numbers into more intelligible format, the total internal surface are is estimated to be equal to the total area of one side of a tennis court.

8. The alveoli in lungs are surrounded by capillaries. Capillaries are actually blood vessels which are the smallest of blood vessels in human body. Scientists say that if all capillaries surrounding the alveoli are unwound and placed end to end, they will cover a staggering 616 miles or 992 kilometers.

9. Human lungs, just like the heart, are protected by the rib cage in chest. The lungs are connected to the spinal cord and the chest bone (or sternum).

10. When humans breathe in or inhale, the lungs expand. This expansion is possible only when diaphragm squeezes. The diaphragm is actually a small dome-shaped muscles seated right below the lungs. If the diaphragm malfunctions, one will experience breathing difficulties.

Interesting Human Lungs Facts: 11-15

11. Our mouth is directly connected to the lungs. In our throat, we can feel a large tube which is the wind pipe or technically known as trachea. Just behind the wind pipe is another tube that runs down from our mouth to the stomach and is known as esophagus. Interestingly, both trachea and esophagus share the same opening, which is why we can breathe using our mouth.

12. Our lungs have taste capabilities. A research in 2010 showed that human lungs contain taste receptors capable of detecting only bitter taste. Studies revealed that whenever these taste receptors encounter any kind of bitter taste, they help the airways to relax. This finding hence became a major area of study for treating asthma.

13. At the time of birth, a baby’s lungs are not inflated and are actually filled with a fluid that is secreted by the lungs. When the baby moves out of the birth canal, a sudden change in environment and temperature triggers the first breath which usually takes place 10 seconds after the baby is delivered from the birth canal.

14. Human lungs consist of special cells which are responsible for the production of mucous. This mucous is then pushed up and out of the lungs by special tiny hair. The mucous is our first line of defense against dangerous microbes that enter our body while breathing. The mucous captures these microbes and prevents them from entering the lungs.

15. Lungs play a pivotal role when it comes to talking or making sound. Our larynx is placed right above our wind pipe. This larynx is the voice box. It contains two small ridges known as vocal cords that open and close to produce sound. The amounts of air we push through the vocal cords from our lungs actually control the volume and pitch when we talk.

Interesting Human Lungs Facts: 16-20

16. The only site where blood in our body picks up oxygen is the pair of lungs. The alveoli that sit at the smallest airways are surrounded by capillaries or blood vessels. This is where the blood absorbs oxygen from the lungs.

17. The exact same site where oxygen is absorbed by blood is also the site where carbon dioxide is absorbed by the lungs from the blood and this carbon dioxide is then removed from the body by exhaling.

18. No matter how hard we exhale, our lungs will always retain 1 liter of air in the airways. This makes the lungs only human organs that can float on water.

19. Human lungs breathe in and out about 2,100 to 2,400 gallons (8,000 to 9,000 liters) of air every day.

20. The rate at which the lungs inhale and exhale are directed by the brain. The brain is capable of sensing oxygen concentration in air and thereby increases or decreases respiration rate accordingly.